This invention relates generally to apparatus for providing taped coils of sheet material and, in particular, to a coiling mechanism for such apparatus. Large heavy coils of sheet material such as steel, aluminum, or the like, supplied from the mill sometimes need to be slit and rewound into smaller and lighter taped coils more suitable for particular manufacturing operations or retail sale. Apparatus already exists for this purpose and U.S. Pat. No. 3,832,876 discloses an example. In that patent, intermittently operated feed rolls feed a continuous strip of sheet material past an intermittently rotated cut-off and end-bending shaft cooperating with a stationary cut-off bar and a stationary wedge-shaped end-bending bar to sever, reversely bend the severed end, and feed the same to a coiling drum having thereon circumferentially spaced strip end catch bars, one of which grasps the bent end of the severed strip and couples it to the periphery of the rotating coiling drum as after a predetermined length of the strip has been measured off by a strip length measuring unit. During coiling, a cresent-shaped pivoted pressure arm prevents rumpling of the strip being wound thereon. While the severed strip is being completely wound on the coiling drum, a taping device descends and deposits a band of adhesive tape aroung the circumference of the coil on the drum to prevent it from unwinding. The intermittent motions of the rotary cutting and bending shaft, as well as that of the taping unit, are controlled and actuated by the pistons of fluid pressure cylinders which also regulate the starting and stopping of the strip feeding rolls. When the tape has been deposited, as far as is desired, around the periphery of the coiling drum, the tape roll is prevented from rotating by a braking device while the taping device is raised, thereby causing the thus-taut tape to be severed by a knife attached to the taping device. A coil ejector ring is then pushed against the inner end of the coil so as to eject it from the coiling drum.
In the aforedescribed apparatus, the leading edge of the oncoming severed strip of material needs to be bent so that it can engage the catch bars on the coiling drum. Such bending results in a certain amount of material wastage in the coil being wound and also requires relatively complex severing, bending, and coiling mechanisms to sever the web, make the bend, and subsequently cause the bent edge to engage to the coiling drum to enable coiling. In addition, the pressure arm acts on only one side of the coil as it is being wound and, therefore, does not ensure a tightly wound coil. Furthermore, since the coiling drum is of fixed diameter, frictional engagement between the coil and the coiling drum needs to be overcome by the ejector ring as the coil is ejected from the drum.